4 Probability and Statistic Questions
1. In a study of the accuracy of fast food drive-through orders, Restaurant A had 295 accurate orders and 51 that were not accurate.
a. Construct a 95% confidence interval estimate of the percentage of orders that are not accurate.
___ is less than P is less than ___
2. The data given to the right includes data from 41 candies, and 10 of them are red. The company that makes the candy claims that 31% of its candies are red. Use the sample data to construct a 90% confidence interval estimate of the percentage of red candies. What do you conclude about the claim of 31%? Construct a 90 % confidence interval estimate of the population percentage of candies that are red.
Red Blue Brown Green Yellow
0.752 0.976 0.828 0.937 0.785
0.972 0.712 0.961 0.794 0.872
0.961 0.978 0.909 0.997 0.877
0.809 0.738 0.842 0.854 0.902
0.816 0.826 0.917 0.732 0.975
0.915 0.985 0.868 0.732 0.886
0.746 0.922 0.757 0.825 0.808
0.951 0.924 0.926
0.713 0.888
0.977
___ % less than p less than ___ %
3. Here are summary statistics for randomly selected weights of newborn girls: nequals174, x overbarequals28.3 hg, sequals6.1 hg. Construct a confidence interval estimate of the mean. Use a 95% confidence level. Are these results very different from the confidence interval 27.3 hgless thanmuless than29.1 hg with only 14 sample values, x overbarequals28.2 hg, and sequals1.6 hg?
What is the confidence interval for the population mean u?
___ hg less than u less than ___ hg
4. Listed below are student evaluation ratings of courses, where a rating of 5 is for "excellent." The ratings were obtained at one university in a state. Construct a confidence interval using a 98% confidence level. What does the confidence interval tell about the population of all college students in the state?
3.8, 3.1, 4.0, 4.7, 3.0, 4.1, 3.4, 5.0, 4.2, 4.4, 4.6, 3.7, 3.2, 4.0, 4.1
Listed below are student evaluation ratings of courses, where a rating of 5 is for "excellent." The ratings were obtained at one university in a state. Construct a confidence interval using a 98% confidence level. What does the confidence interval tell about the population of all college students in the state?